This invention relates to container closures and, more specifically, it relates to a tamper-indicating press-on, pull-off closure for maintaining pressure in a container whereby the closure and container provide a package which may be readily opened by a consumer without the use of tools.
Several types of tamper-indicating closures are presently used for sealing a container and maintaining pressure in the container. These types of closures are particularly needed in conjunction with packaging beverages. One such type of tamper-indicating closure is a metal twist-off cap which incorporates a severable metal ring which fractures upon twisting of the closure so as to remain on the container neck as a tamper-indicating band when the closure has been removed. This type of closure results in a sharp edge remaining on the closure portion which has been removed and on the tamper-indicating band which remains on the container. These sharp edges are inherently dangerous to the consumer utilizing the package. In addition, a twist-off closure requires more expensive and complicated application machinery than does a simple push-on closure.
Another type of tamper-indicating closure is the pull tab which involves severing a portion of the closure in the form of a pull tab, thereby releasing the pressure from within the container. The closure may then be pulled from engagement with the container by means of the pull tab. This type of closure also is inherently dangerous, as a sharp edge is formed both on the pull tab and on the opening formed in the closure. Thus, there has been a long felt need in the packaging art for a press-on, pull-off closure which incorporates a tamper-indicating feature and eliminates any sharp edges remaining after removal of the closure.